SAN JUAN, P.R. — Hurricane Irma, one of the most powerful Atlantic storms ever recorded, battered the islands of the northeast Caribbean early Wednesday, leaving severe damage in its wake as it barreled toward the Virgin Islands and Puerto Rico.

Irma, a Category 5 storm packing winds of up to 185 miles an hour, first made landfall at 2 a.m. on Barbuda, and later in the morning passed directly over St. Martin, the National Hurricane Center reported. There were reports of flooding, major damage to buildings, and severed electricity and phone service on those islands and Saint Barthélemy and Anguilla.

The four “most durable” buildings on St. Martin were destroyed, the French interior minister, Gérard Collomb, said at a cabinet meeting in Paris, “which means that in all likelihood the more rustic buildings are probably totally or partially destroyed.”

In the afternoon, the heart of the storm passed over the British Virgin Islands, the Hurricane Center reported. At 2 p.m., the hurricane’s eye was seven miles northwest of Road Town, capital of the territory, and 20 miles northeast of St. Thomas, in the U.S. Virgin Islands.

As the hurricane continued to move west-northwest, it was projected to rake northeast Puerto Rico later in the day, with the core of the storm remaining over water north of the island.

Devastating storm surges were expected to put parts of Turks and Caicos and the southern islands of the Bahamas 15 to 20 feet underwater on Thursday.